Lid assembly for a processing system to facilitate sequential deposition techniques

ABSTRACT

A lid assembly for a semiconductor processing system is provided. The lid assembly generally includes a lid having a gas manifold mounted on a first side and a baffle plate mounted on a second side. The gas manifold is configured to deliver a plurality of gases to a plenum defined between the baffle plate and the lid. The gases are mixed within a recess formed in the baffle plate before exiting into the processing system through a singular passage.

RELATED APPLICATIONS

[0001] This application claims benefit of United States ProvisionalApplication No. 60/305,970, filed Jul. 16, 2001, which is incorporatedherein by reference in its entirety.

[0002] Additionally, this application is related to U.S. patentapplication Ser. No. 09/798,251, entitled “Lid Assembly for a ProcessingSystem to Facilitate Sequential Deposition Techniques” filed on Mar. 2,2001, U.S. patent application Ser. No. 09/798,258, entitled “ProcessingChamber and Method of Distributing Process Fluids Therein to FacilitateSequential Deposition of Films” filed on Mar. 2, 2001, U.S. patentapplication Ser. No. 09/605,596, entitled “Bifurcated Deposition ProcessFor Depositing Refractory Metal Layer Employing Atomic Layer DepositionAnd Chemical Vapor Deposition” filed on Jun. 28, 2000, and U.S. patentapplication Ser. No. 09/678,266, entitled “Methods and Apparatus ForDepositing Refractory Metal Layers Employing Sequential DepositionTechniques To Form Nucleation Layers” filed on Oct. 3, 2000, all ofwhich are incorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] This invention relates to semiconductor processing. Moreparticularly, this invention relates to a processing system and methodof distributing fluid therein to facilitate sequential deposition offilms on a substrate.

[0005] 2. Description of the Related Art

[0006] The semiconductor processing industry continues to strive forlarger production yields while increasing the uniformity of layersdeposited on substrates having increasingly larger surface areas. Thesesame factors in combination with new materials also provide higherintegration of circuits per unit area of the substrate. As circuitintegration increases, the need for greater uniformity and processcontrol regarding layer thickness rises. As a result, varioustechnologies have been developed to deposit layers on substrates in acost-effective manner, while maintaining control over thecharacteristics of the layer. Chemical Vapor Deposition (CVD) is acommon deposition process employed for depositing layers on a substrate.CVD is a flux-dependent deposition technique that requires precisecontrol of the substrate temperature and precursors introduced into theprocessing chamber in order to produce a desired layer of uniformthickness. These requirements become more critical as substrate sizeincreases, creating a need for more complexity in chamber design andfluid flow technique to maintain adequate uniformity.

[0007] A variant of CVD that demonstrates superior step coverage is asequential deposition technique known as Atomic Layer Deposition (ALD).ALD has steps of chemisorption that deposit monolayers of reactiveprecursor molecules on a substrate surface. To that end, a pulse of afirst reactive precursor is introduced into a processing chamber todeposit a first monolayer of molecules on a substrate disposed in theprocessing chamber. A pulse of a second reactive precursor is introducedinto the processing chamber to form an additional monolayer of moleculesadjacent to the first monolayer of molecules. In this manner, a layer isformed on a substrate by alternatingly pulsing an appropriate reactiveprecursor into a deposition chamber. Each injection of a reactiveprecursor is separated by an inert fluid purge to provide a new atomiclayer additive to previous deposited layers to form a uniform layer onthe substrate. The cycle is repeated to form the layer to a desiredthickness. The control over the relatively small volume of gas utilizedin each pulse is problematic. Pulse frequency is limited by the responsetimes of valves and flow lag within the chamber's gas delivery system.The lag is at least partially due to the relative remote position ofcontrol valves to the process chamber. Consequently, ALD techniquesresult in a deposition rate that is much lower than typical CVDtechniques.

[0008] A need exists, therefore, to reduce the time required to depositfilms employing sequential deposition techniques.

SUMMARY OF THE INVENTION

[0009] Provided is a lid assembly for a semiconductor system, anexemplary embodiment of which includes a support having opposed firstand second surfaces, with a valve coupled to the first surface. A baffleplate is mounted to the second surface. The valve is coupled to thesupport to direct a flow of fluid along a path in an original directionand at an injection velocity. The baffle plate is disposed in the pathto disperse the flow of fluid in a plane extending transversely to theoriginal direction. The proximity of the valve to the baffle plateallows enhanced rate and control of fluid disposed through the lidassembly.

[0010] In one aspect of the invention, one embodiment of a lid assemblyfor a semiconductor processing system includes a lid having a gasmanifold coupled to a first surface and a baffle plate coupled to asecond surface. The gas manifold includes a body having a first channel,a second channel and a third channel extending therethrough. The baffleplate includes a recess formed in a first side of the baffle plate anddefining a plenum with a second surface of the lid. The plenumcommunicates with the first, second and third channels via a pluralityof inlet channels disposed in the lid. The baffle plate has a centerpassage disposed therethrough which provides a singular passagewaybetween the plenum and the second side of the baffle plate. Optionally,any combination of the lid, gas manifold or baffle plate mayadditionally include features for controlling the heat transfertherebetween.

[0011] In another aspect of the invention, a baffle plate fordistributing gases into a semiconductor processing chamber is provided.In one embodiment, the baffle plate includes a plate having a first sideand a second side. A recess is formed in the first side and defines aplenum adapted to receive gases prior to entering the processingchamber. A center passage is disposed through the plate concentricallyand is concentric with the recess. The center passage provides a singlepassageway between the recess and the second side of the plate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] A more particular description of the invention, brieflysummarized above, may be had by reference to the embodiments thereofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only typical embodimentsof this invention and are therefore not to be considered limiting of itsscope, for the invention may admit to other equally effectiveembodiments.

[0013]FIG. 1 is a simplified top perspective view of a plasma-basedsemiconductor processing system in accordance with one embodiment of thepresent invention;

[0014]FIG. 2 is a top perspective view of one embodiment of a lidassembly of the invention;

[0015]FIG. 3 is a sectional view of one embodiment of a lid assembly ofthe invention;

[0016]FIG. 4 is a sectional view of the embodiment of the lid assemblyof FIG. 3; and

[0017]FIG. 5A depicts a bottom view of one embodiment of a gas manifold;

[0018]FIG. 5B depicts a partial sectional view of the gas manifold takenalong section line 5B-5B of FIG. 5A;

[0019]FIG. 6 is a perspective view of one embodiment of a baffle plate;

[0020]FIG. 7 is a sectional view of the baffle plate taken along sectionline 7-7 of FIG. 6;

[0021]FIG. 8 is a partial sectional view of one embodiment of a mixinglip; and

[0022]FIG. 9 is a cross-sectional view of the processing chamber ofFIGS. 1 connected to various subsystems associated with system.

[0023] To facilitate understanding, identical reference numerals havebeen used, wherever possible, to designate identical elements that arecommon to the figures.

DETAILED DESCRIPTION OF THE INVENTION

[0024] Referring to FIG. 1, a semiconductor processing system 10 inaccordance with one embodiment of the present invention includes anenclosure assembly 12 formed from a process-compatible material, such asaluminum or anodized aluminum. The enclosure assembly 12 includes ahousing 14, defining a processing chamber 16 with an opening 44selectively covered and a vacuum lid assembly 20. The vacuum lidassembly 20 is pivotally coupled to the housing 14 via hinges 22. Ahandle 24 is attached to the vacuum lid assembly 20 opposite the hinges22. The handle 24 facilitates moving the vacuum lid assembly 20 betweenopened and closed positions. In the opened position, the interior of thechamber 16 is exposed. In the closed position shown in FIG. 1, thevacuum lid assembly 20 covers the chamber 16 forming a fluid-tight sealwith the housing 14. In this manner, a vacuum formed in the processingchamber 16 is maintained as the vacuum lid assembly 20 seals against thehousing 14.

[0025] To facilitate access to processing chamber 16 depicted in FIG. 1,without compromising the fluid-tight seal between vacuum lid assembly 20and housing 14, a slit valve opening 44 is disposed in housing 14, aswell as a vacuum lock door (not shown). Slit valve opening 44 allowstransfer of a wafer (not shown) between processing chamber 16 and theexterior of system 10. Any conventional wafer transfer device (notshown) may achieve the aforementioned transfer. An example of aconventional wafer transfer device is described in commonly assignedU.S. Pat. No. 4,951,601, issued Aug. 20, 1990 to Maydan, the completedisclosure of which is incorporated herein by reference.

[0026]FIG. 2 is a top perspective view of one embodiment of a vacuum lidassembly 20. The vacuum lid assembly 20 includes a lid 20 a and aprocess fluid injection assembly 30 to deliver reactive, carrier, purge,cleaning and/or other fluids into the processing chamber 16. The fluidinjection assembly 30 includes a gas manifold 34 mounting a plurality ofcontrol valves, 32 a, 32 b and 32 c, and a baffle plate 36 (shown inFIG. 3). Valves 32 a, 32 b and 32 c provide rapid and precise gas flowwith valve open and close cycles of less than about one second, and inone embodiment, of less than about 0.1 second. In one embodiment, thevalves 32 a, 32 b and 32 c are surface mounted, electronicallycontrolled valves. One valve that may be utilized is available fromFujikin of Japan as part number FR-21-6.35 UGF-APD. Other valves thatoperate at substantially the same speed and precision may also be used.

[0027] The lid assembly 20 further includes one or more, (two are shownin FIG. 1) gas reservoirs 33, 35 which are fluidically connected betweenone or more process gas sources and the gas manifold 34. The gasreservoirs 33, 35 provide bulk gas delivery proximate to each of thevalves 32 a, 32 b, 32 c. The reservoirs 33, 35 are sized to insure thatan adequate gas volume is available proximate to the valves 32 a, 32 b,32 c during each cycle of the valves 32 a, 32 b and 32 c duringprocessing to minimize time required for fluid delivery therebyshortening sequential deposition cycles. For example, the reservoirs 33,35 may be about 5 times the volume required in each gas delivery cycle.

[0028] Gas lines 37, 39 extend between connectors 41, 43 and thereservoirs 33, 35 respectively. The connectors 41, 43 are coupled to thelid 20 a. The process gases are typically delivered through the housing14 to the connectors 41, 43 before flowing into the reservoirs 33, 35through the gas lines 37, 39.

[0029] Additional connectors 45, 47 are mounted adjacent the gasmanifold 34 down stream from the reservoirs 33, 35 and connect to thereservoirs by gas lines 49, 51. The connectors 45, 47 and gas lines 49,51 generally provide a flowpath for process gases from the reservoir 33,35 to the gas manifold 34. A purge gas line 53 is similarly connectedbetween a connector 55 and a connection 57 on the gas manifold 34. Inone embodiment, a tungsten source gas, such as tungsten hexafluoride, isconnected to the first reservoir 33 and a reducing gas such as silane ordiborane is connected to the second reservoir 35.

[0030]FIGS. 3 and 4 are partial sectional views of the vacuum lidassembly 20. The gas manifold 34 includes a body defining three valvemounting surfaces 59, 61, 64 (mounting surface 64 is shown in FIG. 4)and an upper surface 63 for mounting an upper valve 65. The gas manifold34 includes three pairs of gas channels 67 a, 67 b, 69 a, 69 b, 71 a, 71b (71 a and 71 b are shown on FIG. 4) that fluidly couple the twoprocess gases and a purge gas (shown as fluid sources 68 a-c in FIG. 9)to the interior of the processing chamber 16 controllably through thevalves 32 a, 32 b, 32 c, thereby allowing thermal conditioning of thegases by the gas manifold 34 before reaching the valves 32 a, 32 b, 32c. Gas channels 67 a, 69 a, 71 a (also termed thermal conditioningchannels) are fluidly coupled to the connectors 45, 47, 57 and providepassage of gases through the gas manifold 34 to the valves 32 a, 32 b,32 c. Gas channels 67 b, 69 b and 71 b deliver gases from the valves 32a, 32 b, 32 c through the gas manifold 34. The gas channel 71 b deliversgas from the valve 32 c through the gas manifold 34 and into a gaschannel 73. The channels 67 b, 69 b and 73 are fluidly coupled to arespective inlet passage 302, 304 and 306 disposed through the lid 20 a.Gases or other fluids flowing through the inlet passages 302, 304 and306 flow into a plenum or region 308 defined between the lid 20 a andbaffle plate 36 before entering the chamber 16.

[0031] The channel 73 additionally is coupled to the upper surface 63.The valve 65 is disposed between the upper surface 63 of the gasmanifold 34 and a cleaning source 38. The cleaning source 38 is acompact system for providing cleaning reagents, typically in the form offluorine or fluorine radicals, for removing contaminants and depositionbyproducts from the chamber 16. In one embodiment, the cleaning source38 is a remote plasma source that typically includes subsystems (notshown) such as a microwave generator in electrical communication with aplasma applicator, an autotuner and an isolator. The gas channel 73through which the cleaning gases are delivered from the cleaning source38 is additionally connected with the gas channel 71 b that deliverspurge gas to the chamber 16 through the plenum 308 disposed in thebaffle plate 36. In this manner, as purge gas is delivered to thechamber 16, any cleaning reagents remaining in the channel 73 betweenthe gas channel 71 b and the chamber 16 may be flushed and exhaustedfrom the chamber 16 prior to the next deposition process.

[0032] The gas manifold 34 further includes a conduit 75 for flowing aheat transfer medium therethrough, thus allowing temperature control ofthe gas manifold 34. In tungsten deposition processes, for example, thegas manifold 34 is typically cooled. For other processes, such astitanium nitride deposition, the gas manifold 34 may be heated toprevent condensation of the reactive gases within the manifold. Tofurther assist in temperature control of the gas manifold 34, a lowersurface 77 of the gas manifold 34 may be configured to tailor thesurface area contact with a first surface 42 of the lid 20 a, thuscontrolling the thermal transfer between the housing 14 and manifoldthrough the lid 20 a. Alternatively, the housing 14 and manifold 34 maybe configured to maximize the contact area.

[0033] Optionally, a plurality of recesses 28 may be formed in a secondsurface 44 of the lid 20 a that contacts the baffle plate 36. Therecesses 28 allow the contact area between the baffle plate 36 and lid20 a to be tailored to promote a desired rate of heat transfer. Thebaffle plate 36 may alternately be configured to control the contactarea with the lid 20 a as described with reference to FIGS. 6 and 7below.

[0034] Referring to FIGS. 5A and 5B, the lower surface 77 of the gasmanifold 34 is illustrated configured to minimize surface area contactwith the lid 20 a. Each of the three gas channels 67 b, 69 b, 73 passrespectively through bosses 502, 504 and 506 that project from the gasmanifold 34. Each boss 502, 504 and 506 has an o-ring chase 79, 81, 83that respectively surrounds each gas channel 67 b, 69 b, 73 to preventfluids passing therethrough from leaking between the gas manifold 34 andthe lid 20 a. A mounting surface 508 surrounds the bosses 502, 504 and506 and includes a plurality of mounting holes 510 which facilitatecoupling the gas manifold 34 to the cover 20 a. In one embodiment, thegas manifold 34 is fastened by screws threading into blind holes formedin the lid 20 a (screws and blind holes not shown). As the bosses 502,504 and 506 and mounting surface 508 provide a controlled contact areabetween the gas manifold 34 and the cover 20 a, the thermal transfertherebetween can be minimized. The contact area between the gas manifold34 and the cover 20 a may utilize other geometries to tailor the heattransfer therebetween. For example, the lower surface 77 of the gasmanifold 34 can be planar to provide maximum contact area with the lid20 a and thus maximize heat transfer between the lid 20 a and the gasmanifold 34.

[0035] Returning to FIG. 4, temperature control of system 10 may beachieved by flowing a heat transfer medium through a temperature controlchannel 20 gdisposed within the lid 20 a. The temperature controlchannel 20 g is in fluid communication with heat transfer medium supply(not shown) that provides and/or regulates the temperature of the heattransfer medium flowing through the channel 20 g to control (i.e., heat,cool or maintain constant) the temperature of the lid 20 a.

[0036]FIGS. 6 and 7 depict one embodiment of the baffle plate 36. Thebaffle plate 36 is coupled to the lid 20 a opposite the gas manifold 34.The baffle plate 36 is generally comprised of a process compatiblematerial such as aluminum and is utilized to mix and uniformlydistribute gases entering the chamber 16 from the gas manifold 34. Thebaffle plate 36 may be removed from the lid 20 a for cleaning and/orreplacement. Alternatively, the baffle plate 36 and lid 20 a may befabricated as a single member.

[0037] The baffle plate 36 is generally annular and includes a firstside 36 a disposed proximate the lid 20 a and a second side 36 bgenerally exposed to interior of the processing chamber 16. The baffleplate 36 has a passage 700 disposed between the first side 36 a and thesecond side 36 b. A recess 702, typically concentric with the passage700, extends into the first side 36 a. The recess 702 and lid 20 adefine a plenum 716 therebetween. The recess 702, typically circular inform, is configured to extend radially from a center line of the baffleplate 36 to a diameter that extends beyond the inlet passages 302, 304,306 disposed in the lid 20 a so that gases flowing from the inletpassages enters the plenum 716 and exits through the passage 700.

[0038] A bottom 712 of the recess 702 defines a mixing lip 704 thatextends radially inward into the passage 700. The transition from a wall714 of the recess 702 to the bottom 712 includes a radius 710 to assistin directing fluid flow within the recess 702 while maximizing the sweptvolume of the recess 702. Gases flowing into the plenum 716 from theinlet passages 302, 304, 306 are re-directed by the flat surface of themixing lip 704 generally towards the center of the recess 702 beforepassing through the passage 700 and into the process chamber 16. Therecess 702 combined with a singular exit passage for delivering gases tothe chamber 16 (e.g., the passage 700) advantageously reduces thesurface area and orifices requiring purging and cleaning overconventional showerheads having multiple orifices for gas delivery.

[0039]FIG. 8 depicts a partial sectional view of one embodiment of themixing lip 704. The mixing lip 704 may include an optional sculpturedsurface 802 that directs the gas flows towards one another or inducesturbulence to enhance mixing and/or cleaning. The sculptured surface 802may includes any one or combination of turbulence-inducing features suchas one or more bumps, grooves, projections, indentations, embossedpatterns and the like. Alternatively, bottom 712 of the recess 702defining the mixing lip 704 may be smooth. In one embodiment, the mixinglip 704 directs gases moving substantially axially from the lid 20 atransversely towards the center of the passage 700 in either a turbulentflow as depicted by flow lines 804, laminar flow or combination thereof,where the converging gas flows mix before exiting the passage 700.

[0040] The mixing lip 704 may include a rounded tip 806 to assist indirecting the flow through the passage 700 and into the chamber 16 withminimal pressure drop. In one embodiment, the mixing lip 704 includes atransition angle 808 between the tip 804 and the second side 36 b of thebaffle plate 36 to enhance the radial flow and uniformity of fluidsexiting the passage 700 and into the chamber 16.

[0041] Returning to FIGS. 6 and 7, the first side 36 a of the baffleplate 36 may additionally include features for reducing the contact areabetween the baffle plate 36 and the lid 20 a. Providing reduced contactarea allows the baffle plate 36 to be operated at a higher temperaturethan the lid 20 a, which in some processes enhances depositionperformance. In the embodiment depicted in FIG. 7, the first side 36 aof the baffle plate 36 includes a plurality of bosses 602, each having amounting hole 604 passing therethrough. The bosses 602 allow the baffleplate 36 to be coupled to the lid 20 a by fasteners passing through themounting holes 604 into blind threaded holes formed in the lid 20 a(fasteners and threaded holes not shown). Additionally, a ring 606projects from the first side 36 a and circumscribes the recess 702. Thering 606 and bosses 602 project to a common elevation that allows thebaffle plate 36 to be coupled to the lid 20 a in a spaced-apartrelation. The spaced-apart relation and the controlled contact areapermit controlled thermal transfer between the baffle plate 36 and thelid 20 a. Accordingly, the contact area provided by bosses 602 and thering 606 may be designed to tailor the amount and location of the solidto solid contact area available for thermal transfer between the baffleplate 36 and the lid 20 a as a particular deposition process requires.

[0042] Referring to FIG. 9, disposed within processing chamber 16 is aheater/lift assembly 46 that includes a wafer support pedestal 48connected to a support shaft 48 a. The support pedestal 48 is positionedbetween the shaft 48 a and the vacuum lid assembly 20 when the vacuumlid assembly 20 is in the closed position. The support shaft 48 aextends from the wafer support pedestal 48 away from vacuum lid assembly20 through a passage formed in the housing 14. A bellows 50 is attachedto a portion of the housing 14 disposed opposite to the lid assembly 20to prevent leakage into the chamber 16 from between the support shaft 48a and housing 14. The heater/lift assembly 46 may be moved verticallywithin the chamber 16 so that a distance between support pedestal 48 andvacuum lid assembly 20 may be controlled. A sensor (not shown) providesinformation concerning the position of support pedestal 48 withinprocessing chamber 16. An example of a lifting mechanism for the supportpedestal 48 is described in detail in U.S. Pat. No. 5,951,776, issuedSep. 14, 1999 to Selyutin et al., entitled “Self-Aligning LiftMechanism”, which is hereby incorporated by reference in it entirety.

[0043] The support pedestal 48 includes an embedded thermocouple 50 athat may used to monitor the temperature thereof. For example, a signalfrom the thermocouple 50 a may be used in a feedback loop to controlpower applied to a heater element 52 a by a power source 52. The heaterelement 52 a may be a resistive heater element or other thermal transferdevice disposed in or in contact with the pedestal 48 utilized tocontrol the temperature thereof. Optionally, support pedestal 48 may beheated using a heat transfer fluid (not shown).

[0044] The support pedestal 48 may be formed from any process-compatiblematerial, including aluminum nitride and aluminum oxide (Al₂O₃ oralumina) and may also be configured to hold a substrate thereonemploying a vacuum, i.e. support pedestal 48 may be a vacuum chuck. Tothat end, support pedestal 48 may include a plurality of vacuum holes(not shown) that are placed in fluid communication with a vacuum source,such as pump system via vacuum tube routed through the support shaft 48a.

[0045] A liner assembly is disposed in the processing chamber 16 andincludes a cylindrical portion 54 and a planar portion 56. Thecylindrical portion 54 and the planar portion 56 may be formed from anysuitable material such as aluminum, ceramic and the like. Thecylindrical portion 54 surrounds the support pedestal 48. Thecylindrical portion 54 additionally includes an aperture 60 that alignswith the slit valve opening 44 disposed a side wall 14 b of the housing14 to allow entry and egress of substrates from the chamber 16.

[0046] The planar portion 56 extends transversely to the cylindricalportion 54 and is disposed against a chamber bottom 14 a of processingchamber 16 disposed opposite to lid assembly 20. The liner assemblydefines a chamber channel 58 between the housing 14 and both cylindricalportion 54 and planar portion 56. Specifically, a first portion ofchannel 58 is defined between the chamber bottom 14 a and planar portion56. A second portion of channel 58 is defined between the side wall 14 bof the housing 14 and the cylindrical portion 54. A purge gas isintroduced into the channel 58 to minimize inadvertent deposition on thechamber walls along with controlling the rate of heat transfer betweenthe chamber walls and the liner assembly.

[0047] Disposed along the side walls 14 b of the chamber 16 proximatethe lid assembly 20 is a pumping channel 62. The pumping channel 62includes a plurality of apertures, one of which is shown as a firstaperture 62 a. The pumping channel 62 includes a second aperture 62 bthat is coupled to a pump system 18 by a conduit 66. A throttle valve18A is coupled between the pumping channel 62 and the pump system 18.The pumping channel 62, throttle valve 18A and pump system 18 controlthe amount of flow from the processing chamber 16. The size and numberand position of apertures 62 a in communication with the chamber 16 areconfigured to achieve uniform flow of gases exiting the lid assembly 20over support pedestal 48 and substrate seated thereon. A plurality ofsupplies 68 a, 68 b and 68 c of process and/or other fluids, are influid communication with one of valves 32 a, 32 b or 32 c through asequence of conduits (not shown) formed through the housing 14, lidassembly 20, and gas manifold 34.

[0048] A controller 70 regulates the operations of the variouscomponents of system 10. The controller 70 includes a processor 72 indata communication with memory, such as random access memory 74 and ahard disk drive 76 and is in communication with at least the pump system18, the power source 52, and valves 32 a, 32 b and 32 c.

[0049] Although any type of process fluid may be employed, one exampleof process fluids are B₂H₆ gas and WF₆ gas, and a purge fluid is Ar gas.N₂ may also be used as a purge gas. The chamber pressure is in the rangeof 1-5 Torr, and the pedestal 48 is heated in the range of 350° to 400°C. Each of the process fluids is flowed into the processing chamber 16with a carrier fluid, such as Ar. It should be understood, however, thatthe purge fluid might differ from the carrier fluid, discussed morefully below.

[0050] One cycle of the sequential deposition technique in accordancewith the present invention includes flowing the purge fluid, Ar, intothe processing chamber 16 during time t₁, before B₂H₆ is flowed into theprocessing chamber 16. During time t₂, the process fluid B₂H₆ is flowedinto the processing chamber 16 along with a carrier fluid, which in thisexample is Ar. After the flow of B₂H₆ terminates, the flow of Arcontinues during time t₃, purging the processing chamber 16 of B₂H₆.During time t₄, the processing chamber 16 is pumped so as to remove allprocess fluids. After pumping of the processing chamber 16, the carrierfluid Ar is introduced during time t₅, after which time the processfluid WF₆ is introduced into the processing chamber 16, along with thecarrier fluid Ar during time t₆. After the flow of WF₆ into theprocessing chamber 16 terminates, the flow of Ar continues during timet₇. Thereafter, the processing chamber 16 is pumped so as to remove allprocess fluids therein, during time t₈, thereby concluding one cycle ofthe sequential deposition technique in accordance with the presentinvention. This sequence of cycles is repeated until the layer beingformed thereby has desired characteristics, such as thickness,conductivity and the like. It can be seen that the time required duringeach period t₁-t₇ greatly affects the throughput of system 10. Tomaximize the throughput, the lid assembly 20 and the injection assembly30 are configured to minimize the time required to inject process fluidsinto the processing chamber 16 and disperse the fluids over the processregion proximate to the support pedestal 48. For example, the proximityof the reservoirs 33, 35 and valves 32 a-b to the gas manifold 34 reducethe response times of fluid delivery, thereby enhancing the frequency ofpulses utilized in ALD deposition processes. Additionally, as the purgegases are strategically delivered through the lower portion of thepassage 73, sweeping of cleaning agents from the gas manifold 34 andbaffle plate 36 is ensured and process uniformity with smaller processgas volumes is enhanced.

[0051] Although the invention has been described in terms of specificembodiments, one skilled in the art will recognize that variousmodifications may be made that are within the scope of the presentinvention. For example, although three valves are shown, any number ofvalves may be provided, depending upon the number of differing processfluids employed to deposit a film. Therefore, the scope of the inventionshould not be based upon the foregoing description. Rather, the scope ofthe invention should be determined based upon the claims recited herein,including the full scope of equivalents thereof.

What is claimed is:
 1. A lid assembly for a semiconductor processingsystem, said lid assembly comprising: a lid having first and secondopposed surfaces a plurality of controllable flow channels extendingfrom the first and second opposed surfaces; a gas control systemdisposed on the first surface and operably opening and closing thechannels; and a mixer coupled to the second surface of the lid, themixer having a central passage in communication with the flow channels.2. The lid assembly of claim 1, wherein the gas control system furthercomprises: a gas manifold disposed on the lid; and at least one valvecoupled to the gas manifold adapted to control a flow through one of theflow channels.
 3. The lid assembly of claim 1, wherein the gas controlsystem further comprises: a gas manifold disposed on the lid; at leastone valve coupled to the gas manifold adapted to control a flow throughone of the flow channels; and a reservoir coupled to the vavle.
 4. Thelid assembly of claim 1, wherein the gas control system furthercomprises: a gas manifold having an upper surface and lower surface; afirst channel, a second channel and a third channel each extendingthrough the gas manifold and exiting the lower surface; and a fourthchannel extending from the upper surface and coupling to the thirdchannel.
 5. The lid assembly of claim 4, wherein the gas control systemfurther comprises: a cleaning source fluidly coupled to the fourthchannel.
 6. The lid assembly of claim 4, wherein the gas manifoldfurther comprises: a conduit disposed therein adapted to flow a heattransfer fluid therethrough.
 7. The lid assembly of claim 1, wherein thelower surface of the gas manifold further comprises a plurality ofbosses that contact the lid.
 8. A lid assembly for a semiconductorprocessing system, said lid assembly comprising: a lid having first andsecond opposed surfaces, the first and second opposed surfaces having afirst inlet channel, a second inlet channel and a third inlet channeldisposed therethrough; a gas manifold coupled to the first surface ofthe lid, the gas manifold comprising: a body having an upper surface andlower surface; a first channel, a second channel and a third channeleach extending through the gas manifold to the lower surface; and abaffle plate having a first side and a second side, the first sidecoupled to the second surface of the lid and having a recess formedtherein, the recess defining a plenum with the second surface of the lidand fluidly communicating with the first, second and third channels viathe inlet channels disposed in the lid, the baffle plate having a centerpassage disposed therethrough providing a singular passageway betweenthe plenum and the second side of the baffle plate.
 9. The lid assemblyof claim 8, wherein the baffle plate further comprises a mixing lipdefined by a bottom of the recess and the center passage, the mixing liphaving an inner tip disposed radially inwards of the inlet passages. 10.The lid assembly of claim 9, wherein the tip is rounded.
 11. The lidassembly of claim 9, wherein the mixing lip further comprises a sculptedsurface. mixing lip defines an acute angle with the second side of thebaffle plate.
 12. The lid assembly of claim 8, wherein the wherein thefirst side of the baffle plate further comprises a plurality of bossesthat maintain the first side of the baffle plate in a spaced-apartrelation with the second surface of the lid.
 13. The lid assembly ofclaim 12, wherein at least one of the bosses has a mounting holedisposed therethrough.
 14. The lid assembly of claim 8, wherein thefirst side of the baffle plate further comprises a ring circumscribingthe recess that maintains the first side of the baffle plate in aspaced-apart relation with the second surface of the lid.
 15. The lidassembly of claim 8, wherein the first side of the baffle plate furthercomprises a ring circumscribing the recess and a plurality of bossesdisposed radially outward of the ring, the ring and bosses maintainingthe first side of the baffle plate in a spaced-apart relation with thesecond surface of the lid.
 16. The lid assembly of claim 15, wherein thering and bosses extend from the first side of the baffle plate to acommon elevation.
 17. The lid assembly of claim 8, wherein the secondsurface of the lid further comprises a plurality of recesses formedtherein that reduce the contact area with the first side of the baffleplate.
 18. The lid assembly of claim 8, wherein the lid furthercomprises a thermal control channel adapted to flow a heat transferfluid therethrough.
 19. The lid assembly of claim 8, wherein the gasmanifold further comprises a conduit disposed therein adapted to flow aheat transfer fluid therethrough.
 20. The lid assembly of claim 8,wherein the gas manifold further comprises a fourth channel coupledbetween the upper surface and the third channel.
 21. The lid assembly ofclaim 20 further comprising: a cleaning source fluidly coupled to thefourth channel.
 22. The lid assembly of claim 8 further comprising: avalve coupled to the gas manifold; and a gas reservoir fluidly coupledproximate the valve.
 23. The lid assembly of claim 22 furthercomprising: a thermal conditioning channel disposed in the gas manifoldfluidly coupling the valve and the gas reservoir.
 24. The lid assemblyof claim 8 further comprising: a thermal conditioning channel disposedin the gas manifold; and a valve coupled between the thermalconditioning channel and the first channel.
 25. A lid assembly for asemiconductor processing system, said lid assembly comprising: a lidhaving first and second opposed surfaces, the first and second opposedsurfaces having a plurality of inlet channels disposed therethrough; avalve; a gas manifold coupled to the first surface of the lid, the gasmanifold comprising: a body having an upper surface and lower surface; aplurality of gas channels extending through the gas manifold to thelower surface; and a thermal conditioning channel disposed in the gasmanifold fluidly coupled to at least one of the plurality of gaschannels by the valve.
 26. The lid assembly of claim 25, wherein thelower surface further comprises: a mounting surface projecting outwardsfrom the lower surface and maintaining the lower surface of the gasmanifold and second surface of the lid in a spaced-apart relation. 27.The lid assembly of claim 25, wherein the lid further comprises athermal control channel adapted to flow a heat transfer fluidtherethrough.
 28. The lid assembly of claim 25, wherein the gas manifoldfurther comprises a conduit disposed therein adapted to flow a heattransfer fluid therethrough.
 29. The lid assembly of claim 25, whereinthe gas manifold further comprises a cleaning agent supply channelcoupled between the upper surface and one of the plurality of channels.30. The lid assembly of claim 29 further comprising: a cleaning sourcefluidly coupled to the cleaning agent supply channel.
 31. The lidassembly of claim 25 further comprising a gas reservoir fluidly coupledto the valve by the thermal conditioning channel.
 32. The lid assemblyof claim 25 further comprising: a baffle plate having a first side and asecond side, the first side coupled to the second surface of the lid andhaving a recess formed therein, the recess defining a plenum with thesecond surface of the lid and fluidly communicating with the pluralityof channels via the inlet channels disposed in the lid, the baffle platehaving a center passage disposed therethrough providing a singularpassageway between the plenum and the second side of the baffle plate.33. The lid assembly of claim 32, wherein the second surface of the lidfurther comprises a plurality of recesses formed therein that reduce thecontact area with the first side of the baffle plate.
 34. The lidassembly of claim 32, wherein the baffle plate further comprises amixing lip defined by a bottom of the recess and the center passage, themixing lip having an inner tip disposed radially inwards of the inletpassages.
 35. The lid assembly of claim 34, wherein the tip is rounded.36. The lid assembly of claim 34, wherein the mixing lip furthercomprises a sculpted surface. mixing lip defines an acute angle with thesecond side of the baffle plate.
 37. The lid assembly of claim 32,wherein the wherein the first side of the baffle plate further comprisesa plurality of bosses that maintain the first side of the baffle platein a spaced-apart relation with the second surface of the lid.
 38. Thelid assembly of claim 37, wherein at least one of the bosses has amounting hole disposed therethrough.
 39. The lid assembly of claim 32,wherein the first side of the baffle plate further comprises a ringcircumscribing the recess that maintains the first side of the baffleplate in a spaced-apart relation with the second surface of the lid. 40.The lid assembly of claim 32, wherein the first side of the baffle platefurther comprises a ring circumscribing the recess and a plurality ofbosses disposed radially outward of the ring, the ring and bossesmaintaining the first side of the baffle plate in a spaced-apartrelation with the second surface of the lid.
 41. The lid assembly ofclaim 40, wherein the ring and bosses extend from the first side of thebaffle plate to a common elevation.
 42. A lid assembly for asemiconductor processing system having an internal volume, said lidassembly comprising: a lid having first and second opposed surfaces, thefirst and second opposed surfaces having a plurality of inlet channelsdisposed therethrough; a valve; a body having a lower surface coupled tothe first surface of the lid; at least one gas channel extending throughthe body from the lower surface and branching into a first gas channeland a second gas channel; and a third channel disposed through the bodyand fluidly coupled by the valve to the second channel.
 43. The lidassembly of claim 42, wherein the valve is mounted to the body.
 44. Thelid assembly of claim 42 further comprising a reservoir fluidly coupledbetween the valve and a fitting disposed on the lid.
 45. The lidassembly of claim 42 further comprising: a cleaning source coupled tothe first channel.
 46. The lid assembly of claim 42 further comprising:a baffle plate having a first side and a second side, the first sidecoupled to the second surface of the lid and having a recess formedtherein, the recess defining a plenum with the second surface of the lidand fluidly communicating with the first, second and third channels viathe inlet channels disposed in the lid, the baffle plate having a centerpassage disposed therethrough providing a singular passageway betweenthe plenum and the second side of the baffle plate.
 47. The baffle plateof claim 46, wherein the wherein the first side of the baffle platefurther comprises a plurality of bosses extending therefrom thatmaintain the baffle plate and the lid in a spaced-apart relation.
 48. Alid assembly for a semiconductor processing system having an internalvolume, said lid assembly comprising: a lid having first and secondopposed surface; a plenum defined between the first and the secondsurfaces; a plurality of inlet channels disposed through first surfaceand coupled to the plenum; a center passage disposed through the secondsurface and coupled to the plenum providing a singular passagewaybetween the plenum and the second surface of the lid; and a mixing lipextending into the center passage, the mixing lip having an inner tipdisposed radially inwards of the inlet passages.
 49. The lid assembly ofclaim 48, wherein the tip is rounded.
 50. The lid assembly of claim 48,wherein the mixing lip further comprises a sculpted surface. mixing lipdefines an acute angle with the second surface of the lid.
 51. The lidassembly of claim 48 further comprising: a valve; and a gas manifoldcoupled to the first surface of the lid, the gas manifold comprising: abody having an upper surface and lower surface; a plurality of gaschannels extending through the gas manifold to the lower surface; and athermal conditioning channel disposed in the gas manifold fluidlycoupled to at least one of the plurality of gas channels by the valve.